At present, China's largest Fiber Optic Splice Closure market is a single-core optical fiber connector. With the continuous expansion of optical communication applications, especially the gradual optical fiberization of local communication networks, the total demand for optical fiber connectors in China has been continuously expanding in recent years. The average compound annual growth rate in previous years was above 30%. At present, the core network for communications and outdoor optical cables for access networks have already had more mature structures and laying methods adapted to China's national conditions. At the same time, after the development in recent years, indoor fiber optic splice closures also have more mature structures and have sufficient production capacity. However, part of the optical fiber cable that the communication network enters the home is outdoors, and part of it is indoor. It puts forward new requirements for the requirements and laying methods of optical cables. A kind of road surface microgroove fiber optic splice closure based on stainless steel loose sleeve technology developed in our country, with fiber cores up to 48 cores, outside diameter less than 6.0 mm, and cable weight less than 60 kg/km. Among them, the stainless steel tube is not only the loose tube protection tube of the optical fiber terminal box, but also can provide the appropriate optical fiber excess length, and is also the fiber optic splice closure sealing sleeve, which is used to completely isolate the external moisture into the sleeve, and is also the reinforcing member of the fiber optic splice closure. Appropriate cross-section of the steel tube to ensure the cable's tensile properties and crush performance. The stainless steel pipe is filled with a thixotropic water-blocking compound to ensure that the cable meets the requirements of water seepage performance. The outer steel pipe is extruded polyethylene sheath.